SUPERCRITICAL FLUID EXTRACTION FROM A BROWN ALGA BY STAGEWISE PRESSURE INCREASE

The use of supercritical carbon dioxide as an extractant for biological materials is described. Extractions from a mediterranean brown alga were conducted with commercial micro-scale equipment, improved by introducing a sapphire extraction cell, and coupled to a high-pressure vessel in order to collect the extracts. By applying a controlled stagewise pressure increase one obtains separate fractions, the colours of which range from colourless to green, depending on the temperature of the extraction. The results, in terms of weight, colour and analysis by high-performance liquid chromatography and by high-performance thin-layer chromatography, are discussed.